scope-css

Prefix or nest each style selector in a css string. Useful to create namespaced css for components, themes, applications, modular css etc. Also it is tiny.

Usage

const scope = require('scope-css');

scope(`
.my-component {}
.my-component-element {}
`, '.parent');

/*
`
.parent .my-component {}
.parent .my-component-element {}
`
*/

API

css = scope(css, parent, options?)

Return css string with each rule prefixed with the parent selector. Note that parent selector itself will be ignored. Also each :host keyword will be replaced with parent value. Example:

scope(`
	.panel {}
	:host {}
	:host .my-element {}
	.panel .my-element {}
	.my-element {}
`, '.panel');

/*
`
	.panel {}
	.panel {}
	.panel .my-element {}
	.panel .my-element {}
	.panel .my-element {}
`
*/

Options can scope keyframes via { keyframes: bool|prefixStr } option, eg.

scope(`
	.panel {
		animation: infinite loading 4s;
	}
	@keyframes loading {
		from { top: 0; }
		to { top: 100px; }
	}
`, '.panel', { keyframes: true })

/*
`
.panel {
	animation: infinite panel-loading 4s;
}
@keyframes panel-loading {
	from { top: 0; }
	to { top: 100px; }
`)
*/

css = scope.replace(css, 'replacement $1$2')

Apply replace to css, where $1 is matched selectors and $2 is rules for the selectors. It does not do any self/host detection, so use it for more flexible replacements.

scope.replace(`
	.my-component, .my-other-component {
		padding: 0;
	}
`, '$1');

// `.my-component, .my-other-component`

See also

• scoped css polyfill

Credits

Based on this question.